What the FDA labels say about taking them together
Heparin and phytonadione
Phytonadione's FDA label of August 9, 2026 names heparin in its drug interactions section; the heparin labels PlainMeds reads (4) do not name phytonadione.
Check it at the source: the heparin FDA label on DailyMed (effective November 28, 2025, Fresenius Kabi USA, LLC); the phytonadione FDA label on DailyMed (effective August 9, 2026, Hospira, Inc.).
What does the heparin label say about phytonadione?
Heparin's label (effective November 28, 2025) and its 3 other brand-application labels do not name phytonadione in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Heparin Sodium), Fresenius Kabi USA, LLC, effective November 28, 2025 (SPL set d55b4a63-0c04-4874-b74f-9e9b9e8b008c), via openFDA; the full label on DailyMed
What does the phytonadione label say about heparin?
Phytonadione label, drug interactionsShould this occur, higher doses of anticoagulant therapy may be needed when resuming anticoagulant therapy, or a change in therapy to a different class of anticoagulant may be necessary (i.e., heparin sodium).
Source: FDA drug label (Vitamin K1), Hospira, Inc., effective August 9, 2026 (SPL set e8808230-2c44-44c6-8cab-8f29b6b34051), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Heparin | Phytonadione | |
|---|---|---|
| Labeled for | Blood clots (DVT and PE), Atrial fibrillation | n/a |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $1.18 per mL 5,000 unit/mL vial | $8.83 per tablet 5 mg tablet |
| Shortage now | In shortage | No current entry |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once